Director Robert Rodriguez said in his DVD commentary that the day they shot Salma Hayek's love scene with Antonio Banderas, the entire crew showed up to see it. He continued, saying that apart from the actors only he and the script supervisor were in the room.

For most of the killings they used a gun that essentially fired fake blood at the characters instead of squibs. This unfortunately created too realistic of an effect resulting in them having to edit out much of the deaths for the censors.

The bathroom scene before the 2nd bar shootout was directed by Antonio Banderas. Robert Rodriguez said he didn't like using 2nd unit crews and Banderas asked if he could direct the scene, to which Rodriguez agreed.

The bar in the beginning of the film where Steve Buscemi and Cheech Marin talk is an actual bar in Acuna, Mexico called the Corona Club. The bar is a lot cleaner and bigger in reality, but it's like walking right into the movie. They also have quite a few pictures of the stars and crew of the movie on the walls.

Though Quentin Tarantino wasn't initially cast in the movie, the character he plays was based on him. Steve Buscemi was originally cast in the role, but when Tarantino expressed an interest he was immediately given the part.

Robert Rodriguez had originally written a rock version of the song "Malagueña Salerosa" into the screenplay. It would later be performed by his band "Chingon" during the end credits of Kill Bill: Vol. 2 (2004).

MPAA originally gave the movie an NC 17 rating. Many deaths and action scenes had to be heavily cut down for R rating. These include death scenes of Pick Up guy and his friend at the bar and death of Danny Trejo's character. By far the most major excision came at the end of the film, which originally contained a large-scale shootout between El Mariachi, Carolina, Bucho and his thugs at Bucho's mansion. However, owing to the amount of footage the MPAA demanded be removed from the scene, Rodriguez elected to remove the sequence in its entirety, giving the film its final fade-out ending.

Two additional scenes were also deleted featuring the "crotch-gun" (seen in the guitar case). Originally, the gun was used by El Mariachi during the second bar shootout when he uses it to shoot the pony tailed thug in balls before whipping out his pistols from his sleeves and finishing him off. In a second deleted scene, the crotch gun gone off accidentally while Banderas is in bed with Hayek, blowing a hole through the guitar that they were playing.

The movie was originally entitled "El Pistolero" ("The Gunman") to be consistent with the first film, El Mariachi (1992). It was changed at the request of the studio. In Mexico, it was released as "Pistolero".

During the shoot out in the bar Cheech Marin's character is rarely seen. This is because they could only shoot his scenes in the six days they had him, so they made an approximation of what the shot up bar would look like and shot his scenes with it, putting his character behind it for most of the shootout.

The same "penis gun" that Sex Machine uses in From Dusk Till Dawn (1996) can be seen in this movie in the guitar case when Carolina looks inside it. The Mariachi says "it's saved my life many times". That film was also directed by Robert Rodriguez and also starred Salma Hayek.

Santa Cecilia (St. Cecilia) is the patron saint of music. Both Henry Purcell and George Frideric Handel wrote Odes to St. Cecilia's Day (22 November 1683, and 1739, respectively). Few hard facts are known about St. Cecilia. She may have existed only in legend.